The grim task of identifying the bodies of five women burned to death in a limousine began today as authorities tried to determine what caused the vehicle to burst into flames.

A newlywed who was celebrating her bridal shower was among the five women who were killed when the 1999 Lincoln Town Car limousine became an inferno Saturday night as it crossed the San Mateo-Hayward Bridge near San Francisco.

Orville Brown, 46, who was driving the women, told the San Francisco Chronicle one of the passengers tapped on the partition, but since the music was loud, he thought she was asking if she could smoke.

"I said, 'The owner doesn't allow smoking in the car, and we only have four minutes to the destination,'" he said.

Fifteen seconds later, they knocked again, he said, prompting him to roll down the partition. This time he knew there was smoke.

California Highway Patrol Capt. Mike Maskarich said the driver pulled over as the flames quickly spread.

Brown escaped unharmed and four female passengers managed to exit the limousine and are being treated for burns and smoke inhalation, he said.

Three good Samaritans, including an off-duty California Highway Patrol sergeant, jumped in to assist, but were unable to help any of the women trapped inside, Maskarich said.

Firefighters arrived and put out the fire and then found five badly burned bodies huddled near the partition separating the driver's section of the car and the rear passenger area.

"My guess would be they were trying to get away from the fire and use that window opening as an escape route," San Mateo County Coroner Robert Foucralt said.

The bride was identified as Neriza Fojas. Fojas, 31, a registered nurse, was recently married in the United States and was planning a second ceremony in the Philippines next month. Fojas and her friends were on their way to the Crowne Plaza Hotel for her bridal shower, where her husband was waiting, according to the San Francisco Chronicle.

The names of the victims have not been released by investigators and the examinations on their charred bodies is expected to begin today, Foucralt said. He expected the reports to take two to three weeks to complete.

While it was too soon to pinpoint the cause of the fire, Maskarich said the limousine was over capacity on Saturday night.

"This particular vehicle was licensed to carry eight or fewer passengers. As we know, there were nine people in this vehicle," he said.

The owner of the limousine company, Limo Stop, told ABC News in a statement that he's deeply saddened and will do everything possible to investigate and assist authorities.